Free Check Engine Light Scan | Advance Auto Parts

A ReliaScan car diagnostic scan reads your vehicle’s trouble codes to help you understand what triggered the light. It’s a starting diagnostic for car problems. An Advance Auto Parts team member will explain your car diagnostic test results and help you figure out what to do next.

How It Works in 3 Steps:

1. Stop by when your check engine light is on. Visit your local Advance Auto Parts when your vehicle is safe to drive. No appointment needed.
2. We’ll scan your vehicle. A team member connects a check engine light reader to your vehicle to retrieve the stored codes in about two minutes.
3. We’ll talk it through. We’ll show you how to check engine light codes, explain your results, and help you find a part if needed.

What Your Check Engine Light is Telling You

Wondering how to diagnose check engine light problems? Start by checking whether the light is steady or flashing.

Solid vs. Flashing

A solid check engine light means you should have your vehicle checked soon. If it’s running poorly, stop somewhere safe and get help. A flashing light usually indicates an active engine misfire, which can damage the catalytic converter. Pull over safely, turn off the engine, and arrange roadside assistance. 

Systems That Trigger the Light

A check engine light points to issues in these systems:

• Emissions components and oxygen (O2) sensors
• Fuel delivery and fuel management
• Ignition components
• Air intake and airflow sensors
• Evaporative emissions (EVAP) monitoring

Common Causes

The light is often caused by:

• A loose or missing gas cap
• A failing oxygen sensor
• Catalytic converter efficiency problems
• Spark plug or ignition coil faults
• Mass airflow (MAF) sensor errors

Free Scan vs. Full Car Diagnostic: What You Actually Get

So how much is a car diagnostic at a repair shop? Usually around $100, depending on the testing needed. Advance Auto Parts offers a free car scan that tells you which system reported a fault. A full shop diagnostic goes further, telling you which part failed. The free scan can point you toward a possible fix; further testing may be needed to confirm the cause.

Find a Store for Your Free Scan

Searching for “check engine light near me”? Or “car diagnostic near me”? Most Advance Auto Parts stores offer a free scan, no appointment needed. Find your nearest location and come on by.

Frequently Asked Questions

Where can I get a free check engine light scan near me?

Most Advance Auto Parts stores offer the free scan. Use the store locator to find your nearest location, confirm hours, and get directions. No appointment is needed. Most stores are open seven days a week.

Is ReliaScan really free?

Yes. There’s no charge and no purchase required. We’ll read your codes, explain the results, and help you figure out what to do next.

How long does a ReliaScan take?

The scan itself takes about two minutes. Allow extra time for us to explain your results and answer questions.

Can you clear the check engine light?

Clearing a code may turn off the light, but it won’t fix the problem. Ask your store about code clearing. If the issue remains, the light can come back on.

Can I drive with the check engine light on?

If the light is steady and your car feels normal, have it checked soon. If it’s flashing or your car is running poorly, pull over safely and arrange help.

Will ReliaScan work on my vehicle?

The scan works on most 1996 and newer gas vehicles and 1997 and newer diesel vehicles. Your local store can confirm coverage for your make, model, and year.

Common DTC Codes

Catalytic Converter Codes

• P0430 — Catalyst System Efficiency Below Threshold (Bank 2)

EVAP System Codes

• P0456 — EVAP System Small Leak Detected
• P0455 — EVAP System Large Leak Detected
• P0442 — EVAP Emission Control System Leak Detected (Small Leak)
• P0441 — EVAP System Incorrect Purge Flow
• P0446 — EVAP System Vent Control Circuit
• P0496 — EVAP Flow During Non-Purge Condition

Fuel Trim Codes

• P0174 — System Too Lean (Bank 2)